The invention relates to a microvalve array.
Microvalves manufactured by microfabrication are known in the at and are for instance described in the European patent publication 0 485 739 A1. As a rule they possess a multi-layer structure and may inter alia be produced by etching and/or molding.
Owing to the constantly increasing fields of application for microvalve technology there is an increasing need for the performance of complex switching functions in a manner dependent on the control assignment.
The customizing connection together, necessary for this, of several known microvalves is not readily implemented owing to their small overall size.
Accordingly it is one object of the present invention to render possible a need-specific linking instrumentality for control technology on the basis of a multiple arrangement of micromechanical valves with simple features.
This object is to be attained by a microvalve array which comprises a plurality of microvalves collected together as a structural unit and produced by microfabrication, an electronic control means for the actuation of the microvalves and having at least one function preset unit for the programmable grouped functional linking of the microvalves, and a fluid duct system connected with the microvalves, fluid ducts of the said system being individually connected for customization, starting with a standardized predetermined arrangement, in a manner dependent on the functional valve linking, preset with the function preset unit, by opening and/or closing passages.
It is in this manner that a multiple arrangement of microvalves collected together as a structural unit is provided, which on the basis of a base structure with mutual adaptation may be linked both controlwise and also fluidwise more or less at will to produce one or more functional groups. By suitably programming the function preset unit it is possible for the individual valves to be collected together as functional groups, which when operated lead to a manner of operation corresponding to a particular functional pattern so that using the functional groups, higher order valve functions can be emulated or furthermore parallel circuits may be produced for the purpose of increasing the rate of flow. Thus it is possible, with the aid of function preset unit, to set the functionality of the valves so that the microvalves collected together within a functional group cooperate during operation and perform like a valve with the predetermined functionality. In order to ensure a functional variability of the microvalve array in addition the programming possibilities provided on the control side, additional possibilities are provided for as regards flexible customizing switching of the fluid ducts communicating with the microvalves. The same comprise a fluid duct system connected with the microvalves, that is to say there is a multiple arrangement of fluid ducts, wherein starting with a standard predetermined duct arrangement and taking into account the functionality, preset by electrical programming, of the microvalves collected together in groups, an individual customizing switching of the fluid ducts becomes possible by opening and/or closing passages between fluid ducts. Such a programmable multiple arrangement of microvalves renders possible batch manufacturing methods in microtechnology with a saving in costs, since identical microvalve systems may be produced, whose valve functionality is initially set, before use, by programming, that is to say mutual matching of functional control linking and customizing fluid duct switching.
Although for example the German patent publication 4,221,089 A1, the German patent publication 4,003,619 A1, the U.S. Pat. No. 5,322,258, the U.S. Pat. No. 5,417,235, the U.S. Pat. No. 5,640,995 or the German patent publication 3,621,331 A1 disclose multiple arrangements of microvalves, which are in part also able to be electrically operate in a variable manner, there is however no account of variable fluid switching on the basis of the intended control presets.
Further advantageous developments of the invention are defined in the dependent claims.
From the point of view of manufacturing technology a configuration is particularly advantageous in which the microvalves collected together in the microvalve array are all of the same type, as for example of the 2/2 or 3/2 type of switching valve. However it would certainly be feasible to have microvalves of different types in one and same microvalve array.
From the point of view of control technology it is possible for the microvalve array to be so designed that it is self-contained in operation and for it to have a preferably freely programmable internal control program in the control means to produce control signals on the basis of which in connection with the associated functional linking parameters stored in the function preset unit the necessary actuating signals are generated, which are applied in a correspondingly set fashion to the microvalves collected together as a functional group in order to produce the desired manner of operation. As an alternative or in addition the control signals could also be applied via a bus connected with the control means and via such bus feedback to a master control device may take place in case of need.
Programming of the function preset unit(s) can advantageously also take place via a bus communicating with the microvalve arrays control means. Furthermore remote controlled programming without wired connections would be possible.
Preferably the microvalve array comprises a laminated body made up of a plurality of superposed layer elements permanently joined together with an interior space having the microvalves and also the fluid duct system formed therein, the production thereof being preferably by micromechanical processing prior to the fitting together of the individual layer elements.
The opening and/or closing of passages takes place for switching of the fluid ducts by opening and/or sealing passages may f. i. be implemented by the use of a suitable separate switching means. In this respect the reader may imagine having a sort of pin cushion bearing pins arranged in accordance with the desired switching state and which may be depressed into a base containing the fluid duct system and to open passages therein. In accordance with further advantageous development of the invention the fluid duct system is provided at predetermined points with sealing means, whose operation will cause opening or closing of a passage between fluid ducts. Such sealing means could for example take the form of plain plug-like partitions within the fluid duct system, which as needed are removed thermally. Furthermore here micromechanical switching valves could be employed as sealing means, which dependent on the position of switching, would open or close a passage and which for example could be mechanically locked in the respective position of switching. More particularly it would also be possible to have valves, whose principle of function is a piezoelectric, magnetostrictive or memory metal one.
It is furthermore an advantage for the customizing fluid switching of the fluid ducts to be reversible so that one application the same valve array may be readily modified on altering the conditions of use as regards the programming of its functionality. In this case remote control actuation, more particularly using non-wired transmission means, would be possible.
In the following the invention will be described with reference to the accompanying drawings in detail.